1. Field of the Invention
This invention relates to improvements in a camera using film with a magnetic recording portion and provided with a magnetic head for effecting the writing and/or reading of information on the magnetic recording portion of the film and an urging member for urging said magnetic head against the magnetic recording portion of said film.
2. Related Background Art
In recent years, a camera which uses film having a magnetic recording or memorizing portion and which is designed to write photographing information such as shutter speed, aperture value, date and title into said magnetic memorizing portion by a magnetic head, and read out said photographing information as required has been proposed in U.S. Pat. No. 4,977,419, etc.
Further, a camera designed such that a magnetic head writes information into the magnetic memorizing portion of film only when the film is advanced to the next frame after the exposure of one frame of the film is disclosed in WO90/04203 (PCT/US89/04343).
Now, to accurately accomplish the writing or reading of information on film with a magnetic memorizing portion by a magnetic head, it is necessary to make such structure that the magnetic head is urged against the magnetic memorizing portion of the film with some pressure and the magnetic head is positively brought into contact with the magnetic memorizing portion of the film. However, there has been the problem that if the magnetic head is in pressure contact with the film for a long time, the film will be deformed and strain will remain in the film to deteriorate the flatness of the film.
Also, as means for urging a magnetic head against the magnetic memorizing portion of film, there has been proposed a structure in which a pad made of rubber or the like is provided at a location opposed to the magnetic head and the film is pushed by said pad to thereby urge the magnetic memorizing portion of the film against the magnetic head, but again in such structure, there is a problem that if the pad pushes the film for a long time, the film will be deformed and though not so remarkably as in the above-described structure, strain will remain in the film to deteriorate the flatness of the film and in addition, there is the problem that the pad made of rubber or the like may stick to the film to make the subsequent feeding of the film difficult.
Also, in the above-described camera, said magnetic memorizing portion is disposed parallel to film supplying direction and at a predetermined location on the film, and coupled with an increase in the amount of information written and read out, it is necessary that the magnetic head be always positioned at said predetermined location on the film with good accuracy.
The applicant has previously filed a patent application which covers, as a camera suited for this, a camera of such structure that a magnetic head is secured and provided with a film platen movable perpendicularly to the direction of movement of film and pivotable on a plane parallel to the surface of the film and provided with a guide portion for regulating the position relative to the film in the widthwise direction thereof and said pressure plate is biased by a resilient member such as a spring to thereby urge said guide portion against a film edge thereof, thus enabling the magnetic head and the magnetic memorizing portion of the film to be positioned with good accuracy.
However, this camera also suffers from the problem that if the guide member is kept in pressure contact with the film edge for a long time, the film will be deformed and strain will remain in the film to deteriorate the flatness of the film.